<?php
namespace addons\venue\library;

class Jssdk {
    private $appId;
    private $appSecret;

    public function __construct($appId, $appSecret) {
        $this->appId = $appId;
        $this->appSecret = $appSecret;
        //判断文件夹是否存在，不存在则创建 多层次文件夹
        if (!file_exists(RUNTIME_PATH. 'venue/wx')) {
            mkdir(RUNTIME_PATH . 'venue/wx', 0777, true);
        }
        if (!file_exists(RUNTIME_PATH. 'venue/wx/jsapi_ticket.php')) {
            //创建jsapi_ticket.php文件
            $fp = fopen(RUNTIME_PATH . 'venue/wx/jsapi_ticket.php', "w");
            fclose($fp);
        }
        if (!file_exists(RUNTIME_PATH. 'venue/wx/access_token.php')) {
            //创建access_token.php文件
            $fp = fopen(RUNTIME_PATH . 'venue/wx/access_token.php', "w");
            fclose($fp);
        }
    }

    public function getSignPackage($url='') {
        $jsapiTicket = $this->getJsApiTicket();

        // 注意 URL 一定要动态获取，不能 hardcode.
        $protocol = (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off' || $_SERVER['SERVER_PORT'] == 443) ? "https://" : "http://";
        $url = $url ? $url : "$protocol$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]";

        $timestamp = time();
        $nonceStr = $this->createNonceStr();

        // 这里参数的顺序要按照 key 值 ASCII 码升序排序
        $string = "jsapi_ticket=$jsapiTicket&noncestr=$nonceStr&timestamp=$timestamp&url=$url";

        $signature = sha1($string);

        $signPackage = array(
            "appId"     => $this->appId,
            "nonceStr"  => $nonceStr,
            "timestamp" => $timestamp,
            "url"       => $url,
            "signature" => $signature,
            "rawString" => $string
        );
        return $signPackage;
    }

    private function createNonceStr($length = 16) {
        $chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
        $str = "";
        for ($i = 0; $i < $length; $i++) {
            $str .= substr($chars, mt_rand(0, strlen($chars) - 1), 1);
        }
        return $str;
    }

    private function getJsApiTicket() {
        // jsapi_ticket 应该全局存储与更新，以下代码以写入到文件中做示例

        $data = json_decode($this->get_php_file(RUNTIME_PATH. 'venue/wx/jsapi_ticket.php'));
        if (!isset($data->expire_time)  || $data->expire_time < time()) {
            $accessToken = $this->getAccessToken();
            // 如果是企业号用以下 URL 获取 ticket
            // $url = "https://qyapi.weixin.qq.com/cgi-bin/get_jsapi_ticket?access_token=$accessToken";
            $url = "https://api.weixin.qq.com/cgi-bin/ticket/getticket?type=jsapi&access_token=$accessToken";
            $res = json_decode($this->httpGet($url));
            $ticket = $res->ticket;
            if ($ticket) {
                if (isset($data->expire_time)){
                    $data->expire_time = time() + 7000;
                    $data->jsapi_ticket = $ticket;
                }else{
                    $data = [
                        "expire_time" => time() + 7000,
                        "jsapi_ticket" => $ticket
                    ];
                }
                $this->set_php_file(RUNTIME_PATH. 'venue/wx/jsapi_ticket.php', json_encode($data));
            }
        } else {
            $ticket = $data->jsapi_ticket;
        }

        return $ticket;
    }

    private function getAccessToken() {
        // access_token 应该全局存储与更新，以下代码以写入到文件中做示例

        $data = json_decode($this->get_php_file(RUNTIME_PATH. "venue/wx/access_token.php"));
        if (!isset($data->expire_time)  || $data->expire_time < time()) {
            // 如果是企业号用以下URL获取access_token
            // $url = "https://qyapi.weixin.qq.com/cgi-bin/gettoken?corpid=$this->appId&corpsecret=$this->appSecret";
            $url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=$this->appId&secret=$this->appSecret";
            $res = json_decode($this->httpGet($url));
            $access_token = $res->access_token;
            if ($access_token) {
                if (isset($data->expire_time)){
                    $data->expire_time = time() + 7000;
                    $data->access_token = $access_token;
                }else{
                    $data = [
                        "expire_time" => time() + 7000,
                        "access_token" => $access_token
                    ];
                }

                $this->set_php_file(RUNTIME_PATH. "venue/wx/access_token.php", json_encode($data));
            }
        } else {
            $access_token = $data->access_token;
        }
        return $access_token;
    }

    private function httpGet($url) {
        $curl = curl_init();
        curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($curl, CURLOPT_TIMEOUT, 500);
        // 为保证第三方服务器与微信服务器之间数据传输的安全性，所有微信接口采用https方式调用，必须使用下面2行代码打开ssl安全校验。
        // 如果在部署过程中代码在此处验证失败，请到 http://curl.haxx.se/ca/cacert.pem 下载新的证书判别文件。
        curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);
        curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, false);
        curl_setopt($curl, CURLOPT_URL, $url);

        $res = curl_exec($curl);
        curl_close($curl);

        return $res;
    }

    private function get_php_file($filename) {
        return trim(substr(file_get_contents($filename), 15));
    }
    private function set_php_file($filename, $content) {
        $fp = fopen($filename, "w");
        fwrite($fp, "<?php exit();?>" . $content);
        fclose($fp);
    }
}
